Shaft mucker



I United States Patent 1 3,537,601

[72] Inventor Arthur Stevens 3,445,015 5/1969 Sampo et al. 214/138 [2 n App No ggg g alum Primary Examiner-l-lugo O. Schulz n 2] Filed on. 1.968 A omey Fetherstonhaugh and Co [45] Patented Nov. 3, 1970 [73] Assign. a Equipment Cmud ABSTRACT: A mine shaft mucking machine having a sup- Pon columbh n porting frame adjustably positionable in a mine shaft and a cab rotatably suspended beneath the frame to which one end of a telescopic boom is connected. A digging bucket is pivotally [$4] mg mounted at the free end of the boom and operated by a piston i and cylinder assembly connected by telescopically extensible [52] US. Cl'. and retractable fluid conduits to a motor driven hydraulic [51] hit. v EMU/28 pump mounted in the cab. Fluid actuated means for rotatably [50] Fleld of Search 214/138, positioning the cab, swinging the boom, and telescopically 132, 7 141 g machmes) tending and retracting the boom is also connected by operator controlled valves to the pump. Valve controlled relief con- [56] References Cited duits connect the ump and the telescopically extensible and P UNlTED STATES AT T retractable fluid conduits to permit the passage of fluid 2,440,501 4/1948 Erickson 214/141 the e om and Ihereinto when the boom is telescopically 3,061,122 10/ 19 62 Robbins 214/132 retracted and extended.

' Patented Nov. 3, 1970 3,537,601

Shoot or 2 V INVENTOR x ATTOIZNEYG Patented Nov. 3, 1970 INVENTOR SHAFT MUCKER BACKGROUND OF THE INVENTION This invention relates .to telescopic boom-type mucking machines which are used, particularly, in mine shafts. Mucking machines of this type normally employ a telescopic boom at the free end of which is mounted a bucket which may be of the back hoe, shovel or clam shell type and which may be manipulated to load a skip with broken rock or earth from the bottom of a mine shaft for haulage to a disposal site. Operation of the bucket is usually effected by piston and cylinder assemblies fed by feed lines from a central source of pressurized fluid.

In order to operate the bucket, feed lines to the latter must be long enough to permit the boom to be extended to its full length. The lines, thus become slack when the boom is retracted and form depending loops which are prone to snagging and wear during the operation of the mucker in such close quarters as mine shafts.

Attempts have been made to overcome the problem of loose, hanging feed lines by the provision of telescopic feed lines which extend and retract telescopically concurrently with telescopic extension and retraction of the boom.

Where an operating medium such as compressed air is used, the compressibility of the medium permits telescopic movement of the feed lines, consequently, the development of telescopic type muckingapparatus utilizing this medium has been relatively successful.

SUMMARY OF THE INVENTION The mine shaft mucker of the present invention is of the telescopic boorn-type in which hydraulic fluid is employed to operate the digging tool or bucket connected to the boom so as to provide positive control of all of its movements. The mucker of the present invention is furthermore so constructed as to permit operation of all of its movable parts from a position above the telescopic boom so as to eliminate the hazards normally associated with mine shaft mucking operations.

In the present invention, the mucker comprises a vertically movable supporting member disposed in the mine shaft having an operator and boom carrying carrier mounted therebelow for rotation about a vertical axis. A telescopic boom having a main section and a telescopic section is connected for swinging movement about a horizontal axis to the carrier, the telescopic section having a bucket operably connected at its free end. A source of pressurized hydraulic fluid, having a fluid reservoir associated therewith, is connected to hydraulically actuated means through valves controlled bythe operator for rotatably operating the carrier and swinging and telescopically extending and retracting the boom. Hydraulic fluid from the pressure source is fed to a double acting piston and cylinder assembly connecting the telescopic section of the boom and the bucket, through telescopic feed conduits extending longitudinally of the boom and said conduits having sections connected to the main and telescopic sections thereof for move ment therewith. Relief means in the form of fluid relief conduits connect the feed lines and reservoir and are provided with valves which, when the boom is extended, permit the free flow of fluid from the reservoir to the feed lines and which, when the boom is retracted, open at a predetermined fluid pressure in the feed lines to permit the flow of oil back to the reservoir.

The mine shaft mucker is also provided with hydraulically operated stabilizermembers which are movable into engagement with the walls of the mine shaft so as to stabilize the entire mucker when the boom is operated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation, partly in section, of mine shaft mucking apparatus constructed in accordance with this invention, and shown, arranged in a mine shaft,

FIG. 2 is a front view of the mucking apparatus of FIG. 1,

FIG. 3 is a schematic plan of a mine shaft,

FIG. 4 is an enlarged sectional view taken on the line 4-4 of FIG. 2,

FIG. 5 is a sectional view taken on the lines 5-5 of FIG. 4, and

FIG. 6 illustrates, schematically, a portion of the hydraulic system associated only with the operation of the bucket.

' DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the reference numeral 1, see FIG. 3, designates a vertical mine shaft, having shoring members 2, from the bottom of which blasted rock and the like is removed by the use of a skip 3. The skip is suspended on a cable operated from a conventional hoist, not shown, at the upper end of the mine shaft.

The mucking apparatus accorded the reference numeral 10 includes an open, rigid, main or supporting frame 11, preferably composed of vertical members 12 and horizontal members 13. This main frame 11 is also supported by cable 15 which may be operated through suitable hoisting equipment, not shown, to enable it to be progressively lowered as the shaft is excavated and to be removed therefrom when the shaft is completed.

Arranged along opposite sides of the main frame 11 are vertically elongated stabilizing bars 16, each of which is swingably connected for lateral movement to the main frame by swinging struts 19 so as to permit it to be swung into and out of engagement with the shoring members 2 of the mine shaft. Hydraulically operated rams 20 are connected between the main frame 11 and the stabilizing bars in for operating the letter. These stabilizing bars are operated outwardly against the shoring members of the mine shaft when the main frame 11 has been suitably positioned therein so as to obtain lateral stability of the main frame.

At the lower end 22 of the main frame, a cab 23 is rotatably suspended. The cab is composed of heavy frame members 34 suitably arranged and interconnected so as to be rigid, the size of the cab being such that an operator may seat himself comfortably therewithin.

As illustrated, reference FIGS. 1 and 2, the cab has an elongated, upwardly projecting, large diameter tubular casing 35 securely fastened to an upper frame member 34 of the cab, said casing having an external annular flange 36 at its upper end and an external annular flange 37 adjacent its lower end. The upper annular flange 36 is seated on a ball bearing and race assembly 38 which is supported by an annular plate 40 securely fastened to one of the horizontal members 13 of the frame and through which the casing projects. A ball bearing and race assembly 41 is seated on the lower annular flange 37 for providing rolling friction of the latter with an annular plate 42 also secured to one of the horizontal members of the frame. Rotation of the cab relative to the main frame is effected through a geared connection of a small hydraulic motor 44, mounted on the cab with a large diameter annular gear 46 secured in a suitable manner, such as by bolts 47 to the lowermost horizontal frame members 13 of the main frame 11 in concentric relationship with the casing 35.

Swingably mounted on a horizontal pivot pin 50 mounted on the cab, is a hollow, elongated telescopic boom 51. This boom is of two part construction having a main boom section 52, pivotally mounted at one end 53 on the pivot pin. Into the other end 54 of the main section slidably extends a telescopic section 55. Both main and telescopic sections are of rectangular or boxed shaped cross sections so as to be slidable but nonrotatable relative to each other, (see FIG. 5). At its end 54 the main section has rectangularly shaped guide member 54a which slidably embraces the telescopic section 55 and at its inner end 56 the telescopic section is provided with exterior rectangularly shaped guide member 57 which slidably and snugly flts against the main boom section 52. At the outer end 58 of the telescopic section a digging and carrying bucket 59, preferably of the back hoe type, is pivotally mounted on a pivot pin 60 for rotation about a horizontal axis. Referring to FIG. 1, it will be observed that the pivot pin 60 of the bucket is offset from the central axis of the telescopic section and that the bucket has an operating lever portion 68 confronting the open outer end 59 of said telescopic boom section.

The boom is swingably operated by means of a double acting piston and cylinder assembly 70, the cylinder 71 of which is pivotally connected, in a suitable manner, to the framework of the cab 23 at a point remote from the pivotal connection of the boom thereto and the piston 72 of said assembly 70 is pivotally connected, in a conventional manner, to the main boom section 52 so that the axis of the piston and cylinder 70 has an angular relationship to the longitudinal axis of the boom.

Telescopic extension and retraction of the boom is effected by means of a piston cylinder assembly 80 mounted within the boom and extending longitudinally thereof. The cylinder 81 of the assembly 80 is mounted on the pivot pin 50 and the piston 82 thereof is connected to a pin 83 extending transversely of and connected to the telescopic boom section 55.

Operation of the bucket 59 is effected through the operation of a double acting piston and cylinder assembly 90, the cylinder 91 of which is pivotally connected, in a conventional manner, to the pin 83 and the piston 92 of which has a pivotal connection with the lever arm 68 of the bucket.

The supply of pressurized hydraulic fluid for operating the rams 20 and the piston and cylinder assemblies 70, 80 and 90 emanates from a positive-type, hydraulic pump 100, preferably electrically driven, which is mounted, in a suitable, conventional manner on the casing 35 so as to be rotatable therewith. This pump 100 has a reservoir 101 and main lines 105 and 106 extend from the pump and reservoir 101 respectively to an operator controlled valve assembly 108 mounted in the cab. From the valve assembly 108 extend conduits 109 having a connection through a conventional rotary union 110 with the hydraulic rams 20. Conduits 112 are also extended from the valve assembly to the hydraulic motor 44 and piston and cylinder assemblies 70 and 80 are likewise connected to said valve assembly via conduits 113 and 114, respectively. In order to prevent snagging of the conduits 114, they are extended through the hollow main boom section to their connection with cylinder 81.

In order to supply hydraulic fluid to cylinder 91 of piston and cylinder assembly 90 a pair of telescopic feed conduits 116 and 117 are employed. These feed conduits extend interi orly of and longitudinally of the boom and each has a fixed section 119 which is rigidly secured as by brackets 120 to the main section ofthe boom and also has a telescopic section 122 which is rigidly secured as by brackets 123 to the telescopic section of the boom. The telescopic sections. 122 extend inside the fixed sections 119 and are provided with suitable sealing means, not shown, at their interior ends which slidably and sealably engage the inner surface of the fixed conduits. Flexible conduits 125 are employed to connect the feed conduits 116 and 117 to the head and tail ends, respectively, of cylinder 91 and similar flexible conduits 126 connect both of the conduits to the main lines 105 and 106 through the valve assembly 108.

It will be appreciated that extension or retraction of the boom will result in corresponding extension and retraction of the feed conduits 116 and 117. In order, therefore, to provide for the escape of fluid from the feed conduits when the piston is retracted and to permit fluid to enter these feed conduits when the boom is extended, both feed conduits are placed in direct communication with the reservoir by means of relief conduits 130 and 131, respectively, which bypass the valve assembly 108. These relief conduits may be in the form of flexible hoses or the like, connecting directly, the fixed sections 119 of the feed conduits and the main line 106 as illustrated schematically in FIG. 6.

It is to be noted that the full displacement of the piston 02 and the cylinder 91 of assembly is several times greater, than the full displacement of either one of the feed conduits 116 and 117 when the latter are moved between a fully extended and full retracted position whereby when a quantity of fluid equal to the full displacement of one of the feed conduits is injected into either the head end or tail end of the cylinder 91 only minimum movement of the piston and consequently, minimum movement of bucket, will result.

The relief conduits and 131 are each provided with check valves 133, see FIG. 6, which freely permit the passage of fluid from the reservoir, through mainline 106 to the feed conduits 116 and 117 but prevent the return passage of fluid therethrough. These relief conduits are also provided with spring urged relief valves of conventional design which, consequently, need not be described in detail, and which are arranged in parallel with the check valves 133. These relief valves operate to open the relief conduits to the passage of fluid from the feed conduits 116 and 117 when the fluid pressure in the latter reaches a predetermined value. The relief valves 135 are preferably situated in the cab adjacent the valve assembly 108 and are of the adjustable type so as to permit adjustment of said predetermined pressure.

The valve assembly 108 may be provided with separate operating levers and the like for controlling the operation of each of the hydraulically operated elements, however, it is preferred that a type of valve assembly be chosen which will permit complete operation ofthe mucker with only two levers. Valve assemblies of this last-mentioned type are well known in the trade and need not be described or illustrated in detail.

The operation of the bucket in conjunction with the'telescopic extension and retraction of the boom may best be described with reference to FIGS. 1, 4 and 6. In order to extend the boom from a retracted to an extended position with the bucket in a digging position, as illustrated in solid lines in FIG. 1, the valve assembly is operated to extend the boom. As the boom extends, the check valves 133 will open to permit fluid to flow from the reservoir to the feed conduits as they extend in conjunction with the boom thereby maintaining the bucket in its digging position. The valve assembly 108 is then operated to inject fluid into the head end of the cylinder 91 so as to move the piston towards the tail end thereof thereby swinging the bucket, in a loaded position, into a carrying position as illustrated in the dotted lines in FIG. 1.

Upon retraction of the telescopic section of the boom and consequent telescopic retraction of feed conduits, the fluid pressure in the latter will increase. When said fluid pressure exceeds the opening pressure of relief valves 135 the latter will permit escape of fluid from the feed conduits to the reservoir. As escape of fluid from the feed conduits must be prevented when the bucket is being loaded through the operation of the piston and cylinder assembly 90, the relief valves 135 are so adjusted that they will not open until the fluid pressure in the feed conduits exceeds that which is required to operate the piston 92 for loading the bucket and maintaining the loaded bucket in its carrying position. It will be evident that the check valves 133 will permit the fluid to flow from the reservoir to the feed conduits to enable the boom to be extended, with the bucket in any position.

The bucket, when loaded, will always tend to swing to an unloading position so as to move the piston 92 towards the head end of the cylinder 91. Fluid in feed conduit 116 will, therefore, always be maintained at a greater pressure than the fluid in feed conduit 117. Due to the inequality of fluid pressures on opposite sides of piston 92 there will be a tendency for the bucket to move from its loaded carrying position towards its unloading position, whenever the boom is extended or retracted.

During extension of the boom and consequent extension of the feed conduits the required fluid, to maintain feed conduit 116 full, will be obtained from the head end of cylinder 91 whereas fluid from the reservoir will flow, via relief conduit 131 and feed conduit 117, into the tail end of said cylinder 91 thereby permitting the piston to move towards the head end of said cylinder. During retraction of the boom and consequent retraction of feed conduits, the relief valve in relief conduit 130 will open before the relief valve in relief conduit 131. The fluid displaced in feed conduit 116, therefore, during retraction thereof, will pass into the reservoir and thefluid displaced during telescopic retraction of feed 117 will pass into the tail end of cylinder 91, again causing the piston 92 to move towards the head end of said cylinder.

I This movement of the piston 92 during telescopic extension and retraction of the boom can be overcome by gradually feeding pressurized fluid into feed conduit 116- as the boom is extended or retracted so as to maintain the piston 92 at the tail end of the cylinder 91 thereby preventing movement of the bucket from its carrying position. It will be, appreciated that this type of operation may require some skill on the part of the operator. Where the operator is relatively unskilled and cannot carry out this operation or when a skilled operator forgets to inject the necessary quantity of pressurized fluid into the head end of the cylinder 91 when theboom is extended or retracted, the disproportionate fluid capacities of cylinder 91 and feed line 116 will result in only minimal movement of the piston 92 away from the tail end of cylinder-91 when feed line 116 is moved between fully extended and fullyretracted positions. Consequently, this will result in only minimal movement of the bucket so as to prevent discharging of a load carried by the latter. I

It will be seen that the mine shaft mucking a .iparatus, herein described, may be operated by relatively unsl illed personnel. Furthermore, as the hydraulic fluid carrying conduit associates with the telescopic action of theboor l. and the operation of the bucket are hiddenwithin the boom itself, they are not liable'to damage due to wear or. snagging. on mine shaft timbers and the like. j

lclaim:

1.- Mine shaft mucking apparatus comprising a vertically movable supporting structure adapted to be disposed in a mine shaft, a rotatable member rotatably connected to and projecting below the supporting structure for rotation about a vertical axis, a telescopic boom swingably connected at one end to the rotatable member for swinging about a horizontal axis, said boom having a main section and a telescopic section slidably connected to said main section and having a bucket operably mounted at the freeendof said telescopic section, a source of pressurized hydraulic fluid having a fluid reservoir associated therewith, operator controlled hydraulically actuated means connectable to thefluid source for independently operating the rotatable member and the boo m and for telescopically extending and retracting-the latter, a double acting piston and cylinder assembly located within the boom operably connecting the telescopic section of the; boom and bucket for moving the latter through varied operational positions. fluid tight telescopicfeed conduits extending longitudinally of and within-the boom for carrying fluidunder pressure to said assembly, one end of each feed conduit'being connected to the main section of the boom-and the other end of each conduit being connected to the telescopic section of the boom for movement therewith, operator controlled. valve means for selectively connecting the feed conduits to the fluid source and reservoir, relief conduits connecting the feed con-v duits and the reservoir and automatically operated valve means in said reliefconduits for permitting the flow of fluid from the reservoir to the feed conduits and for-permitting the fluid to return to the reservoirwhen the fluid pressure in the feed conduits exceeds a predetermined value.

i 2. Mine shaft mucking apparatus as claimed in claim 1 in which the boom is tubular and said feed lines extend interiorly thereof.

3. Mine shaft mucking apparatus as claimed in claim I in which said automatically operated valve means comprises a check valve in each reliefconduit operable to permit one way flow of fluid from the reservoir to the feed conduits and a spring closed relief valve in parallel with each check valve adapted to open at a predetermined pressure in said feed conduits to permit the escape of fluid from the latter back to the reservoir.

4. Mine shaft mucking apparatus as claimed in claim 1 in which said rotatable means comprises a cab for supporting an operator rotatably connected in a depending position to the supporting structure and'a horizontal pivot pin mounted on the cab t0 which one end of the main section of the boom is pivotally connected.

5. Mine shaft mucking apparatus as claimed in claim 1 including hydraulically operated laterally movable brace means mounted on the supporting structure movable into and out of engagement with the walls of the mine shaft for stabilizing the supporting structure therein.

6. Mine shaft mucking apparatus as claimed in claim 1 in which said source of pressurized fluid comprises a positivetype hydraulic pump and motor means mounted on said rotatable member for rotation therewith.

7. Mine shaft mucking apparatus as claimed in claim 1 in which the size relationship of the telescopic feed conduits relative to the piston and cylinder assembly is such that fluid displaced by one feed conduit, when the boom is moved between a fully extended and fully retracted position and when injected into the cylinder of said assembly, will result in only minimal movement of the piston thereof.

8. Mine shaft mucking apparatus as claimed in claim 1 in which the main and telescopic boom sections have a boxshaped cross-sectional configuration.

9. ln mine shaft mucking apparatus of the telescopic boom type, having a main boom section and a telescopic boom section slidably connected to said boom section, and a bucket mounted on the free end of the telescopic boom section the improvement comprising a double acting hydraulic piston and cylinder assembly connecting the telescopic boom section and bucket for moving the latter through varied operational positions, a source of pressurized hydraulic fluid having a fluid reservoir, telescopic fluid feed conduits extending longitudinally of the boom and connecting the source of pressurized hydraulic fluid and'said piston and cylinder assembly, one end of each of said feedconduits being connected to the main section of the boom and the other end being connected to the telescopic section of the boom for movement with the latter and having a slidable, fluid-sealed connection with said main tube, fluid relief conduits connecting the feed conduits and the reservoir, and automatically operable valve means associated with said relief conduits for permitting free flow of fluid from the reservoir to the feed conduits and for permitting the return flow of fluid to the reservoir through the relief con duitswhen the fluid pressure in said feed conduits attains a predetermined value.

10. In mine shaft mucking apparatus of the telescopic boom type, having a main boom section and a telescopic boom section slidably connected to said main boom section, and a bucket mounted on the free end of the telescopic boom section the improvement comprising a double acting hydraulic piston and cylinder assembly connecting the telescopic boom section and bucket for operating the latter through varied operational positions, a source of pressurized hydraulic fluid having a fluid reservoir, telescopic fluid feed conduits extending longitudinally of .the boom and connecting the source of pressurized hydraulic fluid and said piston and cylinder assembly, one end of each of said feed conduits being rigidly connected to the main section of the boom and the other end being rigidly connected to the telescopic section of the boom for movement with the latter and having a slidable, fluidreservoir when the fluid pressure in said feed conduits attains a predetermined value.

11. Mine shaft mucking apparatus as claimed in claim 10 in which the feed conduits extend interiorly of the boom. 

